Electric stop motion for looms



Dec. 23, I969 w. A. ROBERTS ETAL 3,485,972

ELECTRIC STOP MOTION FOR LOOMS Filed June 26, 1968 49 INVENTORS WILLIAM A. ROBERTS JAMES w. TERRELL ATTORNEY United States Patent 7 3,485,972 ELECTRIC STOP MOTION FOR LOOMS William A. Roberts, Paterson, and James W. Terrell, Little Falls, N.J., assignors to Roberts Unique Loom Parts, Inc., Paterson, N.J., a corporation of New Jersey 1 Filed June 26, 1968, Ser. No. 740,250

Int. Cl. 1865b 25/14 Us. or. zoo-61.18 6 Claims ABSTRACT on THE DISCLOSURE Various loom stop motions are known for shutting off the loom automatically when certain undesirable conditions prevail. Among the prior art stop motions are included some which stop the loom automatically in response to improper operation of the cloth take-up mechanism. Examples of such prior art stop motions are contained in United States Patents 762,426, issued June 14, 1904, to Marcoux, and more recently, 2,771,911, issued Nov. 27, 1956 to Holt. In the Holt patent," an electrical switch is provided in the Stop motion circuit of the loom including a toggle arm actuator disposed near the sand roll and near the cloth web leaving the sand roll prior to passing around a guide roller and, finally, onto the take-up roll. If the cloth clings improperly to the sand roll and tends to wind up thereon excessively, the cloth will engage and left the toggle switch actuator completing a circuit through the electrical stop motion thus stopping the loom and preventing damage to the cloth and/or loom.

There are certain disadvantages to the Holt arrangement one of which is the necessity for arranging the switch actuator in the close quarters between the two customary guide rolls on one side of the Sand roll. Furthermore, the operation of the switch is dependent upon contact with the cloth web tending to wind up with the sand roll and the precise behaviour of the cloth is difiicult to predict and is not always the same, resulting sometimes in the improper or premature or late operation of the switch, which stops the loom.

The invention herein is an improvement on the Holt arrangement and on the prior art in general through the provision of an electromechanical device which is more foolproof in operation, less delicate, easier to install and adjust, and which does not depend for its proper operation upon contact with the segment of cloth which is tending to wind up on the sand roll and thus depart from its correct path of travel. Instead, the operation of the invention is based upon positioning a small low friction sensing wheel in constant contact with the periphery of the take-up roll. As long as the take-up roll turns properly in one direction to collect cloth thereon, an electrical contact element associated with the sensing wheel will be positioned to open the stop motion circuit so that the loom will operate normally. If and when the cloth tends to cling to the sand roll and wrap around the same excessively, this will have the immediate effect of pulling the take-up roll rearwardly or momentarily reversing it. correspondingly, the turning of the small sensing wheel will reverse and this will instantly move the contact element to a stop motion circuit closing position and immediately stop the loom. The electrical contact element has only a light friction connection 3,485,972 Patented Dec. 23, 1969 ice with the constantly turning sensing wheel and the contact element moves a limited amount between fixed stop elements and cannot interfere with the continuous movement of the wheel.

BRIEF DESCRIPTION OF THE DRAWING FIGURES FIGURE 1 is a fragmentary vertical section through a loom take-up mechanism and showing the cloth following its normal path around the sand roll in full lines and also showing the abnormal path of the cloth by means of a broken line, the invention also being shown applied to the loom in FIGURE 1.

FIGURE 2 is an enlarged fragmentary elevation, partly in section, 'taken on line 22 of FIGURE 1.

FIGURE 3 is a cross sectional view taken on line 33 of FIGURE 2.

FIGURE 4 is an enlarged fragmentary side elevational view of the invention device.

FIGURE 5 is a diagrammatic view including the stop motion electrical circuit and elements of the invention mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail, wherein like numerals designate like parts throughout the same, the numeral 10 designates a portion of the loom frame adjacent the cloth take-up end of the loom, the cloth being shown at 11 passing over the breast beam 12 and then beneath a first guide roller 13 and around the usual sand roll 14 and then around a second guide roller 15' and, finally, around the cloth take-up roll 16 disposed in the usual manner on the loom. The normal or proper path of movement of the cloth around the several rolls is clearly shown in FIGURE 1. Continuing to refer to this figure, a condition is shown at 17 by means of a broken line where a section of cloth is improperly adhering to the sand roll 14 and tending to wrap up excessively thereon rather than passing normally around the guide roller 15 and onto the take-up roll 16. It is this improper condition or tendency which the invention instantly detects by sensing a change in the normal movement of the cloth take-up roll 16 and establishing a circuit with the stop motion and immediately stopping the loom before damage occurs.

The invention proper comprises a first bracket arm 18 secured rigidly to the girt 19 on the loom frame. The arm 18 includes two slotted sections and is longitudinally extensible and adjustable and is locked in the proper adjusted length by a pair of clamp screws 20. A second two-piece bracket arm 21 also longitudinally extensible is pivoted at 22 to the bracket arm 18 and is resiliently biased toward contact with the cloth take-up roll 16 by a torsion coil spring 23 having ends 24 and 25 bearing upon the respective arms 18 and 21. The spring 23 surrounds the pivot element 22 as shown in detail in FIG- URE 2. The two adjustable sections of the bracket arm 21 are clearly shown in FIGURE 2 including their locking or clamping screws 26 similar to the screws 20.

The upper section 21 of arm 21 carries a pair of rigid spaced parallel extensions 27 and 28 which serve as stop elements for a movable electrical contact element, to be described. As shown in FIGURE 1, the extensions 27 and 28 project away from the take-up roll 16, the bracket arm 21 being arranged beneath the take-up roll and inclined, as shown. An axle 29 is fixedly Secured to the arm section 21' near the top thereof and extends at right angles thereto between the extensions 27 and 28. The axle 29 is secured to the arm section 21' by screw-threaded engagement including a locking nut 30, as shown in FIGURE 3. The axle projects for a substantial distance beyond one side of the arm section 21'.

Freely rotatably mounted upon the axle 29 is a nonmetallic preferably plastic or hard rubber sensing wheel 31 engaging spacer means 32 at one side of its hub and having frictional contact on its opposite flat side 33 with a metallic flat disc or plate 34 surrounding the axle 29 loosely. A relatively light compressible coil spring 35 urges the disc 34 into frictional contact with the wheel surface 33 and the tension of the spring may be adjusted by changing the position of a collar 36 on the axle, said collar having a clamping set screw 37, FIG- URE 4. There is sufiicient friction between the disc 34 and sensing wheel 31 whereby turning of the wheel in either direction will turn or carry the disc with it.

The disc 34 carries a generally L-shaped electrical contact arm 38 suitably secured thereto and this contact arm, as shown, extends between the two stop extensions 27 and 28 which will positively arrest movement of the contact arm with the wheel 31, although the wheel may continue to turn at all times. A small insulating block or piece 39 is secured at 40 to the extension 27 and an electrical contact element 41 is anchored to the insulating block 39 as at 42 by a terminal screw, electrically connected in FIGURE with a Wire 43 leading to a conventional stop motion 44 connected by another wire 45 with a transformer winding 46 grounded at 47. The other transformer winding 48 is connected with power at 49.

Continuing to refer to FIGURE 5, the axle 29 is grounded through the loom frame and the contact arm 38 carried by the disc 34 is shiftable into and out of electrical contact with the element 41 so as to complete or interrupt the stop motion circuit at the proper times.

OPERATION During normal or proper behavior of the cloth 11 on the sand roll 14, the sensing wheel 31 will ride on the periphery of the take-up roll 16 and turn in the direction of the arrow in FIGURE 1 and the contact arm 38 will be urged by the frictional contact between the disc 34 and wheel surface 33 into engagement with the stop extension 28. The wheel 31 will turn continuously and the disc 34 will simply slide over the surface 33. With the contact arm 38 thus held against the extension 28 and away from contact element 41, the stop motion circuit is opened and the loom operates normally to weave cloth and to take-up cloth on the take-up roll 16.

When the cloth at 17 behaves improperly and tends to wind up on the sand roll, 14 excessively, this will have the effect of pulling back the cloth web 11 from the take-up roll 16 and reversing the normal movement of the takeup roll, and consequently reversing the rotation of the sensing wheel 31 in contact therewith. When this occurs, the friction between the wheel 31 and disc 34 will cause the contact arm 38 to shift with the wheel into electrical contact with the element 41, closing the stop motion circuit and immediately stopping the loom so that the situation can be rectified.

It may thus be seen that the essence of the operation resides in the sensing wheel 31 which constantly rolls on the periphery of the cloth take-up roll 16 and has constant friction driving contact with the disc 34. The disc 34 and Wheel surface 33 have relative sliding motion as the disc is restrained due to contact between the arm 38 and extension 28 or element 41.

It is to be understood that the form of the invention" herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention.

What is claimed is:

1. A stop motion for a loom responsive to motion of the loom cloth take-up roll comprising a sensing wheel element having rolling contact with the peripheryof the take-up roll, means supporting said sensing wheel element on the loom and holding it in said rolling contact with the take-up roll, a first electrical contact element having a friction drive connection with the sensing wheel element whereby the first contact element may turn with the sensing wheel element between fixed limits and may then slide relative to the sensing wheel element without further turning, and a second electrical contact element in the path of movement of the first contact element when the latter is turning in one direction with the sensing wheel element, said second contact element electrically connected in a loom stop motion circuit so as to energize said circuit when engaged by the first contact element.

- 2. A stop motion for a loom as defined in claim 1, wherein said means supporting the sensing wheel element comprises a bracket arm structure on the loom near one side of the take-up roll including a pivoted part having sensing wheel element journaled thereon for free rotation in either direction, and a spring means biasing the pivoted part and sensing wheel element toward the take-up roll constantly.

3. A stop motion for a loom as defined in claim 2, wherein said bracket arm structure includes a fixed arm portion having a pivotal connection with said pivoted part, and the pivoted part and fixed arm portion are each formed with two adjustable sections, and means to lock the sections in selected relative positions.

4. A. stop motion for a loom as defined in claim 1, wherein said first contact element includes a contact arm projecting radially beyond said sensing wheel element, a friction disc secured to the contact arm and bearing frictionally against one face of the sensing wheel element, and an adjustable resilient means engaging said disc to vary the degree of friction between the disc and sensing wheel element.

5. A stop motion for a loom as defined in claim 4, and a pair of spaced rigid stop elements on said means supporting the sensing wheel element and projecting be yond the periphery of the sensing wheel element, said contact arm movable between said rigid stop elements, and said second contact element secured to one of said rigid stop elements in the path of movement of said contact arm.

I 6. A stop motion for a loom as defined in claim 2, and an axle member secured to said pivoted part of the bracket arm structure, said sensing wheel element freely rotatable on the axle member, said first contact element including a friction disc engaging one end face of the sensing wheel element, a coil spring surrounding the axle member and bearing upon the friction disc, and an adjustable collar on the axle member engaging one end of the coil spring.

References Cited I UNITED STATES PATENTS 2,636,951 4/1953 Fahringer 20061.l3 2,699,702 1/1955 Cuber 200-6118 2,771,911 11/1956 Holt 139339 H. O. I ONES, Primary Examiner US. Cl. X.R. 139-339 

